A great 5-video tutorial: 35minutes on YouTube (6 tomatoes / 2.5 hours for non-stop studing by coding).
Author's Github (py2), My Github (py3).

Differences in my Github code:

• py3, not py2
• using on_put() to test validity of input json from client
• using on_delete() to test params (just to test, should NOT be used in real-world)
• using another route /test2?x=1&y=3 to test params

Usage in Nix:

pip3 install falcon gunicorn
gunicorn app:api # in the folder of app.py

Usage in Win (tested in bash sub system):

pip3 install falcon waitress
waitress-serve --port=8000 app:api

The json content that is sent from client:

{
    "method": "get-name",
    "name": "Sunny",
    "x": "22",
    "y": 33,
    "x1": 11,
    "y1": "55"
}

Note: string-number is suggested in json instead of int/float directly, to avoid different formats of big numbers.

The client is insomnia, (Postman is too slow, SoapUI has not been tested).

Routers: see github discussion

To deploy with Nginx on Ubuntu 16.04: ref-DigitalOcean

The official quick-start example is also very easy (they are using a static long-life object which is good for caching data).